docs: def from_json(cls, json_obj):
          """
          Constructs a Variable from the provided json-object.
  
          Example
          --------
          >>> import json
          >>> with open("path_to_file.json") as infile:
          >>>     var = Variable.from_json(json.load(infile))
          """
          return cls(json_obj["name"], lb=json_obj["lb"], ub=json_obj["ub"], type=json_obj["type"])